Bathtubs are usually installed before tiling. However, if you are looking to add a bathtub to an otherwise finished space, or at least already tiled space, you may want to know if any issues will arise from placing the tub on top of the floor tile.
Can you install a bathtub over tile? Yes, depending on the type of tile and the tub being installed. However, it is important that you understand and consider the potential pitfalls of this installation strategy.
However, a few complications need to be considered when going this route. Let’s look at some factors.
Why Install A Bathtub Over Tile?
If you are adding a bathtub to an existing bathroom space or other area of your home that already has finished flooring, it would be most cost effective and less labor intensive to install directly over the tile.
The first question to ask is what kind of bathtub you are installing. Some standard styles include:
- Separate bathtub basin and wall kits
- One-piece tub and shower unit
- Drop-in style tub, like whirlpool or garden tub
- Clawfoot tubs
Separate bathtub basin and wall kits are often used to replace old bathtub combos in bathroom remodels. They are easier to handle and can be used to cover existing shower walls.
Drop-in tubs are usually installed into a prepared box covered in tile or another solid surface.
Clawfoot tubs sit on top of the floor, with exposed legs and basin. With either of these styles, the tile flooring must already be in place.
For the purposed of this article, we are discussing the one-piece tub and shower unit. It is a fiberglass tub molded into shape, with the walls attached as a single unit. (source)
These tubs are usually installed in the rough-in phase of construction, but you can install them in a partially finished/finished space.
The second question to answer is what kind of tile you are installing the bathtub over. There are many kinds of tile on the market today, and each has particular properties to consider.
|Tile Material||Durability/Care||Ease of Install||Other Info|
|Vinyl Tile||Very Durable||Easy to install||Low cost|
|Ceramic/Porcelain||Somewhat Durable, more care to maintain||Reasonably easy to install||Most common, Cold|
|Glass Tiles||Make sure graded for flooring||Similar to ceramic||Can be slippery|
|Stone Tile||More care/sealing required||Similar to ceramic||More expensive|
|Plastic Laminate Tile||Doesn’t withstand moisture||Easy DIY||Less choice of styles|
|Linoleum Floor Tiles||Inhibits microorganism growth||Easy DIY||Expensive|
|Cork Tiles||Not moisture proof||Reasonably easy||Warm and soft|
|Historic Tiles||Many varieties of material, care||Asbestos possibility||Can be difficult to repair/restore|
If you are installing a bathtub over tile, it is important to consider the maintenance and durability of the tile.
Some tile choices, like vinyl or linoleum, have little chance of damage and no grout lines. Others, like ceramic or stone, create more potential for breakage and further complications.
Let’s look at what might go wrong and how to mitigate it.
Four potential issues can arise when installing a bathtub over a more delicate tile like ceramic, porcelain, or stone tile. These are:
- Subfloor support: Often the area where you want to install a bathtub does not have enough structural support to take the weight of a bathtub. You may need to strengthen the subfloor underneath the bathtub, negating the desire to keep the tile intact.
- Plumbing Installation: If plumbing is not already in place, you will need to create holes in the tile to install the bathtub drain. This can potentially break more tiles than you want and spread into the exposed flooring area.
- Leveling: When installing a bathtub, you must level the tub, often with shims. If the tile flooring does not extend all the way to the wall, and therefore all the way under the corners of the tub, you may find leveling more difficult. However, if the whole space is tiled this shouldn’t be an issue.
- Damage to tile: Of course, the obvious consideration is damage to the tile under and around the bathtub when you drop it into place. Maneuvering a large one-piece fiberglass tub creates potential for breakage or cracking of tiles or grout lines.
Looking at these four issues in more depth, you can see how installing a bathtub over tile may require more preparation of the tile under the tub and also the area surrounding it.
This is especially true if the tile has an intricate pattern or large grout lines, you will want to ensure the installation process does not harm the exposed tile.
Even if you are able to install the tub successfully, a couple of problems could show up after time.
- Water damage: This should not be a problem if the tub is installed and plumbed properly. But remember, you still need to caulk the edge of the tub where it meets the floor to stop water leakage under the tub.
You cannot avoid the caulk line, even though the tile pattern continues under the tub.
- Cracks in grout/tile: Over time, the weight of water in the tub and extra stress placed on the tiles could crack the grout lines and tiles under it. This could spread into the surrounding area.
If the subfloor is sufficiently supported, tiles properly installed, and tub resting on a supportive surface, this should not be a problem.
You can install a bathtub over the existing floor tile. However, the preparation of the space is just as important as the installation. You must ensure the subfloor under the tile is strong enough to support the weight of a bathtub.
You should inspect the quality of the tile and grout and make any repairs necessary. And finally, you should take extra care on installation to not damage the tiles.
Some of our other bathroom articles that may help: